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Showing result 1 - 5 of 191 swedish dissertations matching the above criteria.

  2. 1. Potential of Organosolv Lignin Nanoparticles as a Sustainable Flotation Reagent : Towards a Low-Carbon Footprint Mining Industry

    Author : Katerina Hruzova; Ulrika Rova; Saija Luukkanen; Luleå tekniska universitet; []
    Keywords : TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Organosolv lignin particles; Nanoparticles; Flotation reagent; Copper recovery; Biokemisk processteknik; Biochemical Process Engineering;

    Abstract : The green transition is driving a steep increase in the demand for minerals, which has put the focus on more responsible and sustainable mining practices as there is a growing pressure on mining operations to minimise their environmental footprint, mitigate risks in neighbouring communities, and decrease the consumption of natural resources. In 2022, mineral froth flotation was used to recover 18 million tonnes of copper from copper ore, accounting for 80% of total copper mine output. READ MORE

  4. 2. New Reactions with Allyl- and Allenylboron Reagents : Transition-Metal-Catalyzed and Transition-Metal-Free Carbon-Carbon Bond Formation Processes

    Author : Dong Wang; Kálmán J. Szabó; Jianbo Wang; Stockholms universitet; []
    Keywords : NATURVETENSKAP; NATURAL SCIENCES; carbon-carbon bond formation; cross-coupling; organoboron compound; allylboron reagent; allylation; transition metal; metal carbene; allenylboron reagent; transition metal free; diazo compound; tosylhydrazone; quinone; organisk kemi; Organic Chemistry;

    Abstract : Organoboron compounds have been widely used in carbon-carbon bond formation reactions in organic synthesis and catalysis. This thesis is focused on cross-coupling reactions of allyl-, allenylboronic acids and their ester derivatives via transition metal catalysis or transition-metal-free processes. READ MORE

  5. 3. Novel Applications of Benziodoxole Reagents in the Synthesis of Organofluorine Compounds

    Author : Nadia O. Ilchenko; Kálmán J. Szabó; Cristina Nevado; Stockholms universitet; []
    Keywords : NATURVETENSKAP; NATURAL SCIENCES; trifluoromethylation; hypervalent iodine; Togni reagent; difluorination; iodofluorination; organisk kemi; Organic Chemistry;

    Abstract : This thesis concerns method development of new synthetic routes by applying electrophilic hypervalent iodine reagents, such as trifluoromethyl-benziodoxole (Togni reagent) and fluoro-benziodoxole. The first project involved the addition of an oxygen moiety and trifluoromethyl group across double and triple bonds (both groups derived from the hypervalent iodine reagent). READ MORE

  6. 4. Metal Mediated Synthesis. Synthetic and Mechanistic Investigations of Conjugate Addition and Reductive Amination

    Author : Anders Johansson; Chalmers tekniska högskola; []
    Keywords : NATURVETENSKAP; NATURAL SCIENCES; halosilane; all-trans-geranylgeraniol; copper reagent; primary amines; S -geranylcitronellol; iminium salt; alfa; cuprate; beta-unsaturated; lithium iodide; borane dimethyl sulfide complex; reductive amination; conjugate addition;

    Abstract : The thesis is divided into two separate parts, one treating conjugate addition and the other reductive aminations. The first part of the thesis is concerned with organocopper promoted conjugate addition to .alfa.,. READ MORE

  7. 5. Development and Applications of Hypervalent Iodine Compounds : Powerful Arylation and Oxidation Reagents

    Author : Nazli Jalalian; Berit Olofsson; Viktor V. Zhdankin; Stockholms universitet; []
    Keywords : NATURVETENSKAP; NATURAL SCIENCES; hypervalent iodine compounds; diaryliodonium salts; oxidation; Koser s reagent; arylation; phenols; diaryl ethers; chemoselectivity; organisk kemi; Organic Chemistry;

    Abstract : The first part of this thesis describes the efficient synthesis of several hypervalent iodine(III) compounds. Electron-rich diaryliodonium salts have been synthesized in a one-pot procedure, employing mCPBA as the oxidant. Both symmetric and unsymmetric diaryliodonium tosylates can be isolated in high yields. READ MORE